Moisture set magnetic inks



3,072,577 MOISTURE SET MAGNETIC INKS Lewis F. Miller, New Paltz, and Norman M. Callaghan, Jr., Rhinebeck, N.Y., assignors to International Business Machines Corporation, New York, N.Y., a corporation of New York No Drawing. Filed Dec. 19, 1958, Ser. No. 781,485 1 Claim. (Cl. 252-62.5)

This invention relates to inks and more particularly to moisture-set magnetic inks.

Ink materials are now available which when applied to a surface may be instantaneously affixed thereto by the application of water vapor, steam or the like. These inks are called moisture-set inks. Ink materials are also now available which are used for the production of magnetic records on non-magnetic record media, such as paper. Such magnetic inks contain ferromagnetic'materials in finely divided form, uniformly dispersed in the ink. In printing magnetic data representing characters on statistical cards or business documents it is imperative that the imprint be sharp and that it carry as high a percentage of magnetic material as is possible.

It is an object of this invention to provide a moisture set magnetic ink having particular utility with printing machines used to provide record material for use in business machines, which inks are capable of forming nonsmearing, sharply defined data-representing magnetic deposits on paper sheets, cards and other record materials and are affixed to said record materials by the application of water vapor.

Another object is to provide an ink carrying a high percentage of magnetic material which provides a clear nonsmear imprint of high magnetic stability.

In general the inks of this. invention relate to a vehicle containing a binder constituent comprising a resinous material which is insoluble in water, a liquid carrier component in which the resinous material is dispersed or dissolved, said carrier being miscible with Water, astabilizing agent which increases compatability to water under atmospheric conditions but not under conditions of steam and a magnetic pigment consisting of an evenly dispersed ferromagnetic material of small particle size having either high magnetic remanence in the case of ink for use with the retentive type sensing or a high magnetic permeability in the case of the reluctance type sensing.

MAGNETIC PIGMENT The magnetic pigment may be a retentive type having high magnetic remanence or a reluctance type having high permeability. It consists of a magnetic powder preferably of microns or less in particle size having acicular, cubicle or. round shape. Specific non-limiting examples include ferric oxides in the gamma crystalline form, natural and artificial magnetites, hematites. and ferrites. Proportions up to about sixty-five percent by weight have been successfully employed.

LIQUID CARRIER AND BINDER under application of steam or water vapor. Examples include organic resinous polymeric materials such as phenolics, Vinsol, which is a petroleum hydrocarbon insoluble resin derived from pine wood and has a melting point of 116 C., maleated and fumarated rosins such as the adducts of maleic anhydride or fumaric acid with rosin, beta-naphthol pitches and the like.

STABILIZING AGENT Minor amounts of a stabilizing agent may be used, between about five and about eight percent by weight. Non-limiting examples are the polyethylene glycol aliphatic homologous series, polyethanolamines such as di and tri, higher molecular Weight clycols such as octylene, wax compounds and wetting agents. Such wetting agents as Nopco 1825-C, an ethoxylated fatty amino amide having a distillation point of 200 C. and, produced by Nopco Chemical Company, Inc.,- the Igepal group of wetting agentsa group of alkyl phenolethylene oxide condensation products produced by General Dyestuffs, Inc-and particularly Igepal CO 630. Another wetting agent that may be used is Venice turpentine sold under the trade name of Veniturp by S. P. Penick and Company.

In addition, a film forming composition such as the protein resins, i.e. zein, the simple protein prepared from corn, dissolved in a glycol such as ethylene glycol may be added. Around 8% by weight is preferable. Zein A resin, included as an ingredient in some of the following examples of ink compositions, is a modified corn protein having a melting point of 180 C. to 200 C. The zein A resin chars before melting, contains 14 amino acids in the full strength and has a molecular weight of 20,000 to 30,000.

A minor amount of a colorant may be employed and suitable colorants are carbon black, dyes and lakes.

The constituents of the ink are prepared and mixed in a conventional fashion and care is taken to evenly disperse the magnetic pigment throughout the vehicle.

Examples of specific inks are as follows:

Example N0. 1

RETENTIVE TYPE Percent Material Function 35 Gamma ferric oxide powder, particle Magnetic pigment.

size .2 to 20 microns high magnetic remanence.

5 Diethanolamine, oleic acid mixture Stability com- 30:70. pound.

31 Fumarated rosin dissolved in ethylene Heavy body varglycol 60:40. nish binder.

i7 Furnarated rosin dissolved in ethylene Medium body varglycol 50:50. nish binder.

8--" Zein resin dissolved in diethylene gly- Film forming com- 00125275. pound.

4 Carbon black, channel type Colorant.

Example No. 2

RELUCTANCE TYPE Percent Material Function 60 Spherical pure iron powder, particle Magnetic high size .2 to 10 microns. permeability.

20 Fumarated ros n dissolved in diethyl- Heavy body varene glycol 60:40. nish binder.

4 Triethanolamine, oleic acid 30:70 Stability coma pound.

4 Wax-rosin mixture diluted with octyl- Do.

ene glycol.

4 impingement type carbon black Colorant.

8 Zein resin dissolved in diethylene Film forming comglycol 25:75. pound.

q i a i Example N0. 3 33% of a 50:50 solution of fumarated Wood resin having a melting point of 150 C. in dipropylene glycol, Percent Material Function 5% of a 30:70 solution of triethanolamine in oleic acid, 6% of a 25:75 solution of zein A resin in diethylene 3(3) ii eiculartsgnthegic m n ip I t :lgifagnetca 5 glycol, 3% of carbon black and 3% of an ethoxylated l 1 e vng Ill i 4 A i f gl fg fgfi ggj g g g l fatty amino amide having a distillation point of 200 C. Tr ie tl iZm bIamine in oleic acid 30:70,. Stabiliby com- References Cited in the file of this patent JOUHG. G ZeinAresinindiethylene glycol 25:75 Fi lmFormcilng UNITED STATES PATENTS ll 3 p e t a black qgo ga htg 697 375 P k J l 2 1393 3 182: "I 2,346,968 Jeuck et al. 'Apr, 18, 1944 2,34 ,9 9 Je k t A 18, 1944 What has been disclosed are specific embodiments of 2 2 g e a1 11 1945 the present invention. Other embodiments obvious to 2606124 z igg Au 1952 those skilled in the art from the teaching herein are 2584909 Leekle L y et a1. July 27, 1954 contemplated to be within the spirit and scope of the 2688 649 Bjorksten Sept 7 1954 following claim.

What is claimed is: OTHER REFERENCES A moisture-set magnetic ink consisting y Weight, Wolfe: Printing and Litho Inks, 4th ed., Macnairapproximately finely divided magnetic p g 2 Dorland 00., New York, N.Y., 1949, pages 187, 315-317. 

